Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Electrical Specifications

Voltage Versus Temperature Chart:






The PCM supplies a 5 volt reference signal and a ground to the ECT signal to the PCM. A high coolant temperature will result in low signal voltage (near 0 volts) and low coolant temperature will result in high signal voltage (near 5 volts)

The ECT sensor uses two different temperature sensing circuits for two temperature ranges - below 50°C and above 50°C. The PCM will shift between a high resistance circuit for low temps and a low resistance circuit for high temps.